Conductor spacers for multiconductor electrical overhead transmission lines



Nov. 18. 1969 E. B. MOORE 3,

CONDUCTOR SPAGERS FOR MULTICONDUCTOR ELECTRICAL OVERHEAD TRANSMISSIONLINES Filed March 6, 1968 2 Sheets-Sheet 1 INVENTOR Epu/N 51 9mm) NQQREATTORNEY Nov. 18. 1969 E. B. MOORE 3,479,441

CONDUCTOR SPACERS FOR MULTICONDUCTOR ELECTRICAL OVERHEAD TRANSMISSIONLINES Filed March 6, 1968 2 Sheets-Sheet 2 77 77 19 v 15 19 i 1 o I w o1 a 74 70 I 1 H1 74 Fla. 1

United States Patent O US. Cl. 174-42 Claims ABSTRACT OF THE DISCLOSUREIn a conductor spacer for multi-conductor electrical overheadtransmission lines having a conductor clamp composed of two jaw partshinged together and connected to a spacer frame by a flexible joint, asingle means serves to draw the jaw parts together to clamp a conductorbetween the jaw parts and to connect the clamp to the flexible joint.

This invention relates to conductor spacers for electrical overheadtransmission lines and concerns such spacers which will accommodaterelative longitudinal movements of the conductors spaced by the spacer.

According to this invention, a conductor spacer for multi-conductorelectrical overhead transmission lines comprises a spacer bar-or frameto hold at least a pair of conductors apart and a pair of clamps one togrip each of said conductors which are to be held apart, each clampcomprising two jaw parts hinged together and means capable of engagingand disengaging at least one of the jaw parts for drawing the jaw partstogether to grip a conductor between the jaw parts, said means alsoserving to attach the clamp to a flexible joint connecting the clamp tothe spacer bar or the spacer frame.

Preferably the flexible joint comprises a rubber bush which, bydeformation, accommodate relative hinging movements of the clamp and thespacer bar or frame, the bush having an inner rigid sleeve part with athreaded bore receiving a screw bolt, the bolt and the sleeve partserving to draw the jaw parts together and to attach the clamp to theflexible joint.

In the preferred form, said sleeve part is fixed to the other of theclamp jaw parts and the bolt engages said one of the clamp jaw parts.

Preferably, also the screw bolt carries a swing washer of elongatedform, and said one of the clamp jaws has a fork the limbs of which arebridged by the washer to engage the fork with the bolt, the washer beingrotatable through 90 upon loosening the bolt, to disengage the fork.

Specific embodiments of the present invention will now be described byway of example, with reference to the accompanying drawings in which:

FIG. 1 is a cross-section of a conductor clamp for a conductor spaceraccording to this invention,

FIG. 2 is a view in the direction of arrow 2 in FIG. 1,

FIG. 3 is a side elevation of a twin conductor spacer employingconductor clamps as shown in FIGS. 1 and 2, and

FIG. 4 is a side elevation of a quadruple conductor spacer employingconductor clamps as shown in FIGS. 1 and 2.

Referring to FIGS. 1 and 2, each conductor clamp comprises two jaw parts10, 11 hinged together as at 12 by means of a hinge pin 13. The clamp isshown in its operative position clamped about a conductor 14. Part of aspacer bar or spacer frame is indicated at 16. The hinge pin lies closeto the conductor on the opposite side ice of the conductor from thespacer bar or spacer frame, that is to say to the outside of theconductor bundle of which the conductor forms a part and the jaw partsextend from the hinge pin, inwardly of the bundle, respectively over andunder the conductor as viewed in FIG. 1 towards the spacer bar or spacerframe. Screw means, hereinafter described, is provided to draw the innerends of the jaw parts together to clamp the conductor 14 between the jawparts 10, 11. The clamp accordingly encloses the conductor and by virtueof the relative transverse position of the conductor with respect to thehinge pin 13 and the clamping screw 29 the clamp is able to take aneffective grip on the conductor, the clamp offering a good mechanicaladvantage.

The clamp is connected to the part 16 by means of a flexible joint 19comprising a cylindrical rubber bush 20. The bush is housed in an eye 21on the part 16 and may be adhesively united with the inner, cylindricalsurface of the eye. The bush 20, which may alternatively be spherical,has an inner, cylindrical, metal part 24 which may be bonded to therubber of the bush. The part 24 is rivetted at one end, as at 26, to thelower clamp jaw part 10 and is provided in its other end with a blind,screw threaded bore 28 which receives the clamping screw 29 which takesthe form of a screw bolt.

The screw bolt 29 carries a swing washer 30 which is of elongatedrectangular form with rounded ends in plan, as shown in FIG. 2, and ofT-shape in the plane through the screw bolt axis parallel with itslonger sides so as to present a central portion 30a of generally squareoutline to fit between interfacing surfaces 32a of fork limbs 32 on theinner end of the upper jaw part 11, and wing portions 30b to overlierecessed step surfaces 32b on the fork limbs, as shown in FIG. 2. Theunder surface of the wing portions 30b and the step surfaces 32b may becorrespondingly curved as indicated in FIG. 1 about a common axisparallel with the axis of the conductor 14.

This allows the washer 30 to tilt on the step surfaces to accommodaterelative angular movements of the clamp jaw parts 10 and 11 duringtightening and untightening the screw bolt 29.

In FIGS. 1 and 2 the clamp is shown gripping the conductor 14 in theinstalled condition of the spacer. The wing portions 30b of the washer30 are seated in the recesses in the fork limbs 32, the washer bridgingthe fork limbs 32 to engage the screw bolt with the fork. In thisposition the washer is prevented from rotating on the screw bolt. Whenthe screw bolt is loosened sufiiciently without disengaging the part 24,the washer is freed for rotation through to align the washer with thegap 35 between the fork limbs. The washer is of a size to pass throughthe gap 35 when aligned with the gap. The jaw part 11 is accordinglyfree to swing upwardly to release the conductor from the clamp.

The screw bolt remains screwed into the bore 28 of the part 24 and thewasher 30 remains captive on the screw bolt. When the cable spacer isinstalled, the reverse procedure is adopted. Installation is carried outfrom a cradle running on the conductors. The construction of clamp withno separate parts to be assembled, ensures that parts cannot be droppedand lost.

The form of clamp illustrated presents a smoothly curved profile withoutprotuberances, edges or points which are likely to give rise to coronadischarge. A good electrical performance is thus obtained.

The rubber bush 20 accommodates relative angular movements of theconductor 14 and the spacer frame so that relative longitudinalmovements of the conductors spaced by the spacer and relative movementsof the conductors in a plane normal to the plane of the conductors,

is permitted. The rubber bush may insulate the clamp electrically fromthe spacer frame.

The rubber bushes assist in damping out low amplitude vibrations of theconductors and prevent or reduce the transmission of vibrations throughthe spacer from one conductor to another.

A twin conductor spacer, according to the invention using clamps andflexible joints as described with reference to FIGS. 1 and 2 is shown inFIG. 3. Two clamps are employed, one for each of the conductors 14, theclamps being carried one on each end of a straight spacer bar 16, byflexible joints indicated at 19.

FIG. 4 illustrates the use of the clamps and flexible joints in aquadruple conductor spacer according to the invention. The clamps arecarried one at each of the four corners of a rectangular spacer frame 60and connected thereto each by a flexible joint 19 as previouslydescribed.

The spacer of FIG. 4 may be modified to incorporate a triangular spacerframe, not shown, carrying three of the clamps as previously described,one at each corner of the triangular frame and each connected to theframe by a flexible joint 19 as previously described.

The spacer frame 60 of FIG. 4 may be of any other convenient shape. Itmay for example be formed by radiating arms there being as many arms, asthere are conductors 14 in a bundle of conductors to be spaced. For fourconductors, an H frame may be employed. The frames need not necessarilybe rigid frames. The frames may be articulated frames.

Spacers according to the invention employing conductor clamps andflexible joints as described with reference to FIGS. 1 and 2 have fewerparts and are more economically produced.

I claim:

1. A conductor spacer for multi-conductor electrical overheadtransmission lines comprising:

a spacer bar or frame to hold at least a pair of conductors apart;

at least a pair of clamps, one clamp gripping each of said conductorswhich are to be held apart, each clamp including:

first and second jaw parts which are hinged together, said first jawpart having a fork-like portion; and means including a screw boltcarrying an elongated swing washer, for releasably engaging the limbs ofthe fork-like portion with the screw bolt for drawing the jaw partstogether to grip a conductor between the jaw parts, said swing washerbeing rotatable upon loosening the bolt to disengage the fork-likeportion; and

a flexible joint including a rubber bush connecting said engaging meansto said spacer bar or frame to form a flexible connection between theclamp and the spacer bar or frame, said rubber bush having an inner,rigid sleeve part fixed to said second jaw part and having a threadedbore receiving said screw bolt, said screw bolt and said sleeve partserving to draw the jaw parts together and to attach said clamp to saidflexible joint.

2. A conductor spacer as claimed inclaim 1 wherein the swing washer isrotatable through upon loosening of the screw bolt, to disengage saidfork-like portion.

3. A conductor spacer as claimed in claim 1 wherein the washer has acentral portion to fit between interfacing surfaces of the fork limbs toprevent rotation of the washer, the washer having wing portions tooverlie the fork limbs.

4. A conductor spacer as claimed in claim 3 wherein the fork limbs haverecessed step surfaces to receive the wing portions of the washer.

5. A conductor spacer as claimed in claim 4 wherein the undersurfaces ofthe wing portions and the step surfaces are correspondingly curved abouta common axis parallel with the axis of the conductors in use of thespacer.

References Cited UNITED STATES PATENTS 3,113,173 12/1963 Horovitz174-146 X 3,263,021 7/1966 Caunt 174-146 X FOREIGN PATENTS 892,423 3/1962 Great Britain. 624,923 9/1961 Italy.

LARAMIE E. ASKIN, Primary Examiner US. Cl. X.R. 24132; 174-146

